Tunneling machine for noncircular bores

ABSTRACT

To bore a noncircular hole a conventional tunneling machine is provided with two or more rotatable cutter wheels mounted at the rear of the machine and rotating about axes parallel, but offset relative to, the main boring head of the machine. The main boring head digs the conventional circular bore. The rear-mounted wheels advance with the machine and dig into the circular bore to form the desired cross-sectional shape- D- or horseshoe-shape, etc.

United States Patent Williamson 1 Feb. 22, 1972 TUNNELING MACHINE FOR NONCIRCULAR BORES Primary Examiner--Emest R. Purser Attorney-Julian Caplan and Gregg, Hendricson and Caplan [5 7] ABSTRACT To bore a noncircular hole a conventional tunneling machine is provided with two or more rotatable cutter wheels mounted at the rear of the machine and rotating about axes parallel. but offset relative to, the main boring head of the machine. The main boring head digs the conventional circular bore. The rear-mounted wheels advance with the machine and dig into the circular bore to form the desired cross-sectional shape-D-or horseshoeshape, etc.

4 Claims, 5 Drawing Figures [72] Inventor: Thomas N. Williamson, San Mateo, Califl [73] Assignee: Jacobs Associates, San Francisco, Calif. a

part interest [22] Filed: Apr. 20, 1970 [21] Appl. No.1 29,998

[52] US. Cl ..299/31, 175/91, 299/60 [51] Int. Cl ..E01g 3/04 [58] Field 01 Search ..299/31, 33, 57, 59, 60, 86; 175/91, 94

[56] References Cited UNlTED STATES PATENTS 1,039,809 10/1912 Rogers ..299/31 I 3,428,363 2/1969 Drescheretal ..299/57 PATENTEDFEB 22 I972 SHEET 2 UF 2 62' 410 I a '90 [/V P7// //7 270 r A a FIG. 4.

INVENTOR.

ATTORNEY TUNNELING MACHINE FOR NONCIRCULAR BORES This invention relates to a new and improved machine for driving tunnels and is characterized by the fact that the resulting bore is noncircular. The invention has particular application for tunneling in firm soil or rock to produce a noncircular bore such as is used in highway or rail tunnels. The invention employs a conventional tunnel boring machine which produces a circular bore and attached to the rear of and driven by said machine are one or more peripheral boring heads whose bores overlap the main bore and shape the sides of the tunnel in the desired manner.

l-leretofore rock boring machines have employed a revolving cutter head, normally equipped with rolling cutters, to produce only a round bore. Since rock and firm soilboring (as distinguished from tunneling in softer materials such as coal) requires a machine which is anchored to the walls of the hole which it has bored and applies several times the machine's weight in a thrust which advances the main boring head, the use of drag cutters, which are satisfactorily used in coal digging, is impractical.- Since noncircular bores are desired for many types of tunnels, the art has employed many inconvenient, expensive means for producing the required shape. The present invention greatly simplifies and economizes in the digging of noncircular tunnels.

A typical example of a tunnel which is produced by means of the present invention is the horseshoe or D" shape which is used in highway and rail tunnels. Such shape is noncircular, particularly at the bottom, to provide a road bed. Another example of the use of the present invention is in the construction of a dual-tangential circular shape which is used in a rapid transit rail tunnel to provide a single tunnel for two trains going in opposite directions. The present invention makes possible the construction of such tunnels in an improved manner. Still another example of the use of the present invention is in mining certain stable minerals (e.g., salt. limestone, oil shale) where relatively large, approximately square openings are desired. The present invention may be used to approach this cross section.

In accordance with the present invention a conventional rock tunnel boring machine is used as the lead element to produce a circular face and cylindrical walls which may be used to position wall anchors for the machine and thus to absorb torque and thrust. The present invention mounts one or two motors on the main tunnel boring machine having rearwardly directed drive shafts parallel to the tunnel axis. A cutter head or heads mounted on the drive shaft to cut circular peripheral bores which overlap the main bore and thus alter the shape of the tunnel. The present invention provides a practical means for the operation ofsuch a machine.

A feature of the invention is the fact that the forward tunneling machine creates the thrust for its own forward progress as well for the rear cutter members. Thus it is unnecessary in the practice of the present invention to employ separate wall anchors for the peripheral cutters.

In a modification of the present invention, the rear radially mounted cutter wheels are attached to the sides of the forward tunneling boring machine by a rigid member and the motors and drive gears are mounted behind rather than in front of the radially mounted cutter heads.

ln another modification of the invention, four or more radially mounted cutter heads are positioned so that two cut the lower corners of the tunnel, thus producing a horseshoe shape, and the other two remove the cusps in the roof between the originally bored tunnel and the lower, radially mounted cutter heads, thus producing a smooth and strong roof.

Another feature of the invention is the fact that the cuttings are removed from the forward tunnel borer by means of bucket pickups on the cutter head. The buckets dump onto a conveyor on the top or bottom of the forward boring machine. The conveyor, which is usually a belt, passes between the cutter heads in the V-shaped opening provided either at the top or the bottom. The cuttings from the peripherally mounted cutters are similarly picked up by buckets and are dumped into the same or another conveyor.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

FIG. 1 is a side elevational view of a machine in accordance with the present invention shown installed inside a tunnel.

FIG. 2 is a sectional view taken substantially along the line 22 ofFIG. 1.

FIG. 3 is a schematic rear elevational view of the machine showing the contour of the tunnel produced thereby.

FIG. 4 is a view similar to FIG. 2 of a modification.

FIG. 5 is a view similar to FIG. 3 of the modification of FIG.

The tunnel of the present invention is formed by boring face 1 1 at the front of the tunnel to produce a circular bore 12 and then to bore offset faces 13 to form arcuate walls 14, the cuts 14 being hereinafter termed peripheral bores.

The tunnel shown in FIG. 3 may be produced by the tunneling machine 16. Said machine is described and illustrated herein schematically since there are numerous commercially available machines. Many other types of machines may be employed, using the teaching of the present invention. The specific machine herein described, has an inner frame 17 from which radially project anchor jacks 18 having pads 19 at their outer ends which firmly engage the wall 12 and function to ab sorb the thrust and torque of the tunneling operation. As the tunnel is constructed, from time to time the jacks 18 are released, the inner frame 17 is moved forward, the jacks 18 are again projected and the machine 16 is thus intermittently advanced. Walking jacks (not shown) support the machine during the time the anchor jacks 18 are retracted. This means of advancing a tunneling machine is well known in the art and is not herein described and illustrated since there are many variations which can be employed.

Surrounding the frame 17 is an outer frame 21 formed with slots 22 which permits the frame 21 to reciprocate longitudinally relative to frame 17 while the jacks 18 are projected. Inner frame 17 carries thrust cylinders 23 which bear against a transverse brace 24 attached to the outer frame 21. Thus, with the inner frame 17 anchored to walls 12, cylinders 23 force outer frame 21 forwardly.

Ahead of outer frame 21 is a main cutter head 26 which carries on its forward face a plurality of roller cutters 27. The cutters 27 are likewise subject to wide variation since there are many means of cutting the face 11. Mounted on outer frame 21 are one or more drive motors 28 having drive shafts 29 which are arranged by gearing (not shown) to rotate head 26. Thrust bearings 31 are interposed between frame 21 and head 26 so that as frame 21 is pushed forwardly the head 26 and cutters 27 are likewise pushed against the face 11.

Associated with head 26 are scoops 32 which are arranged to scoop up the broken rock as head 26 revolves. The broken rock is dumped from scoops 32 onto a conveyor 33 shown schematically as installed along the top of bore 12, the forward end of conveyor 33 being supported by transverse pulley 34 and the opposite end extending to a dump car, all as well understood in the tunneling art.

The machine 16 which has heretofore been described is, as well understood in this art, conventional.

Mounted to the rear of machine 16 and offset laterally and below the central axis of bore 12 are peripheral cutter hubs 41. Projecting radially from hub 41 are blades 42 and mounted near the outer ends of blades 42 are cutters 43 similar to cutters 27. It will be understood that the segmental cutter blades 42 are a preferred form of the invention because they permit access longitudinally of the cutter but circular plates or other means for mounting the cutters 43 may be employed. Scoops 44 similar to scoops 32 are mounted on blades 42 and remove broken rock and deposit same on secondary conveyor 46, the leading end of which is supported by pulley 47. The conveyor 46 extends upwardly and laterally and discharges either onto conveyor 33 or into separate dump cars.

The hubs 41 are similarly subject to considerable modification. In a preferred embodiment of the invention, longitudinally extending shafts 51 are driven by motors 52 mounted on outer frame 21 with gear boxes 53 interposed. A yoke 54 depends from outer frame 21 and hence as the frame 21 is advanced by cylinders 23, the entire support and drive for the blades 42 is similarly advanced. This arrangement makes unnecessary the use of a separate machine for the cutters 43 since the means cutting the peripheral bores 14 is advanced coextensively with the head 26 which cuts the bore 12.

FIGS. 4 and show a modification wherein there are four instead of two peripheral cutters. In many respects the apparatus of FIGS. 4 and 5 is identical to that of the preceding modification and the same reference numerals followed by subscript a are used to designate corresponding parts. Rearward extensions 61 of shafts 51a project beyond cutter hub 41a and drive transmissions 62 which in turn drive shafts 63. The rearward ends of shafts 63 carry upper cutter hubs 64 from which project upper cutter segments 65 having roller cutters 66 on the periphery thereof. A frame 67 supports the rearward ends of shafts 63 so that the cutter segments 65 advance along with segments 42a.

The tunnel shape is shown in FIG. 5. A lower peripheral bore 14a resembles bore 14 of the preceding modification and above bore 14a on each side of the tunnel is an upper bore 14b. By removing the cusp 79 where bores 14a and 14b intersect, a wide tunnel capable of supporting two transit trains operating in opposite directions is produced.

Although the foregoing invention has been described in some detail, by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention and scope of the appended claims.

lclaim:

1. A machine for driving a tunnel with a noncircular bore comprising a frame, means carried by said frame for anchoring said frame to a tunnel bore, a rotatable main cutter head forward of said frame, means mounted on said frame for rotating said main cutter head about first longitudinal axis; means for advancing said main cutter head relativeto said means for anchoring said frame; at least one peripheral cutter head having cutters mounted on the forward face thereof located rearward of said frame; means mounted on said frame for rotating said peripheral cutter head about a second axis, with the arc cut by said peripheral cutter head intersecting the circle cut by said main cutter head, said second axis being parallel, but offset, relative to said first longitudinal axis and means on said frame for advancing said main cutter head and both said peripheral cutter heads while said frame is anchored to said tunnel bore, said last-named means located ahead of said peripheral cutter head.

2. A machine according to claim 1 which further comprises a second peripheral cutter head having cutters mounted on the forward face thereof, and means mounted on said frame for rotating said second peripheral cutter head about a third longitudinal axis parallel to said first axis and offset relative to said first longitudinal axis to balance said second axis, said second peripheral cutter head located opposite said first-mentioned peripheral cutter head.

3. A machine according to claim 2 which further comprises a third and a fourth peripheral cutter head each having cutters mounted on the forward face thereof, and means mounted on said frame for rotating said third and fourth peripheral cutter heads about fourth and fifth longitudinal axes, respectively, each parallel and offset relative to said second and third axis, said third and fourth peripheral cutter heads being located opposite each other and rearward of said first and second peripheral cutter heads.

4. A machine according to claim 2 in which each of said second and third cutter heads as earth pickup means and which further comprises a conveyor for conveying earth longitudinally rearwardly of said machine, said earth pickup means discharging into said conveyor. 

1. A machine for driving a tunnel with a noncircular bore comprising a frame, means carried by said frame for anchoring said frame to a tunnel bore, a rotatable main cutter head forward of said frame, means mounted on said frame for rotating said main cutter head about first longitudinal axis; means for advancing said main cutter head relative to said means for anchoring said frame; at least one peripheral cutter head having cutters mounted on the forward face thereof located rearward of said frame; means mounted on said frame for rotating said peripheral cutter head about a second axis, with the arc cut by said peripHeral cutter head intersecting the circle cut by said main cutter head, said second axis being parallel, but offset, relative to said first longitudinal axis and means on said frame for advancing said main cutter head and both said peripheral cutter heads while said frame is anchored to said tunnel bore, said last-named means located ahead of said peripheral cutter head.
 2. A machine according to claim 1 which further comprises a second peripheral cutter head having cutters mounted on the forward face thereof, and means mounted on said frame for rotating said second peripheral cutter head about a third longitudinal axis parallel to said first axis and offset relative to said first longitudinal axis to balance said second axis, said second peripheral cutter head located opposite said first-mentioned peripheral cutter head.
 3. A machine according to claim 2 which further comprises a third and a fourth peripheral cutter head each having cutters mounted on the forward face thereof, and means mounted on said frame for rotating said third and fourth peripheral cutter heads about fourth and fifth longitudinal axes, respectively, each parallel and offset relative to said second and third axis, said third and fourth peripheral cutter heads being located opposite each other and rearward of said first and second peripheral cutter heads.
 4. A machine according to claim 2 in which each of said second and third cutter heads as earth pickup means and which further comprises a conveyor for conveying earth longitudinally rearwardly of said machine, said earth pickup means discharging into said conveyor. 